diff --git a/runtime/indent/logtalk.vim b/runtime/indent/logtalk.vim
index 5b69663..8e36f86 100644
--- a/runtime/indent/logtalk.vim
+++ b/runtime/indent/logtalk.vim
@@ -1,5 +1,5 @@
 "  Maintainer:	Paulo Moura <pmoura@logtalk.org>
-"  Revised on:	2008.06.02
+"  Revised on:	2018.08.04
 "  Language:	Logtalk
 
 " This Logtalk indent file is a modified version of the Prolog
@@ -42,6 +42,9 @@
 	" Check for clause head on previous line
 	elseif pline =~ ':-\s*\(%.*\)\?$'
 		let ind = ind + shiftwidth()
+	" Check for grammar rule head on previous line
+	elseif pline =~ '-->\s*\(%.*\)\?$'
+		let ind = ind + shiftwidth()
 	" Check for entity closing directive on previous line
 	elseif pline =~ '^\s*:-\send_\(object\|protocol\|category\)\.\(%.*\)\?$'
 		let ind = ind - shiftwidth()